Explosion-engine.



M. SEARS.

EXPLOSION ENGINE. APPLIOATION FILED mm: 14, 1909.

Patented Aug. 30, 1910.

UNITED STATES PATENT OFFICE.

MARTIN SEARS,'I or Los ANGELES, CALIFORNIA.

EXPLOSION-ENGINE.

To all whom it may concern:

Be it known that I, MARTIN "SEARS, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Explosion-Engines, of which the following is a specification.

This invention relates to an improvement in light weight engines of the flying machine class, and it consists in a peculiar arrangement of cylinders and pistons operating through a two cycle system in such a manner that a practical maximum of efliciency is obtained with a concentration of parts tending to a large reduction of weight.

The basis of the engine is a single cylinder having a pair of pistons therein, the explosion chamber being between the pistons.

There are two crank shafts, one at each end' of the cylinder and one of the pistons is connected to each crank shaft. The crank shafts are rotatively connected in such a manner that the pistons move outwardly. and inwardly simultaneously. To one of the crank shafts is also connected a piston reciprocating in a compression cylinder. This compression cylinderis of larger diameter than the explosion cylinder, being preferably of about twice the cross sectional area. The compressed gases are introduced to the combustion space while the two pistons are wide apart, the burnt gases being forced out through the exhaust port by the inflowing fresh gases without the aid of a deflector. The inwardly moving pistons recompress thejcharge and it is then exploded" to drive them apart. The arrangement of the compression cylinder is such that the charge is compressed therein simultaneously with the explosion stroke of the two pistons, the gases compressed thereby being ready for induction into the expanded space between the two pistons when farthest apart.

In the present showing of the invention I have arranged four distinct units of the above described type on one set of crank shafts. The cranks on these shafts are offset in such a manner as to bring. the explosion of the several cylinders into uniform succession, there being in the present form four explosions to each revolution. The number and arrangement of cylinders, however, may be made to suit the needs of any particular case. 7

In the accompanying drawings, Figure l is a sectional plan view of the engine. Fig. 2 is a perspective view of one of the crank shafts. Fig. 3' is a longitudinal vertical ,section of one of the units composing the engine, taken on line 3-3 of Fig. 1.

Referring particularly to the drawings 5' designates a frame which is most conveniently made up into the rectangular shape shown' from rolled angles and channels. This structure affords a light and rigid frame especially adapted for carrying the working parts of the engine. Across the frame angle members '6 extend to carry explosion cylinders 7 and compression cylinders. 8. Explosion cylinders 7 are comparatively long and are about one half the cross sectional area of compression cylinders 8, the piston strokes in the cylinders being equal. The compression cylinders are mounted in a linev across one end of the frame-while the Specification of Letters Patent- Patel lted Aug. 30, 1910. Application filed June 14, 190 9. Serial No. 501,974. I

explosion cylinders are mounted in a line across the frame near the other end. Journaled across the frame in the space between the two sets of cylinders is a crank shaft 19 in Fig. 2. The two cranks at each end of the shaft are disposed oppositely while the two center cranks are arranged at quarters. On the end of the frame outside of cylinders v having four cranks 10 thereon disposedwith I relation to each other in the positlons 'shown 7 is arranged a second crank shaft 11 having 1 I cranks 12 thereon, this crank shaft being similar to crank shaft 9.

y In each of explosion cylinders 7 is a long piston 13 and a short piston 14, the short piston being connected by connecting rod 15.

to crank shaft 11, and the long plston by connecting rod 16 to crank shaft -9.- EX

haust ports 17 of the explosion cylinder are placed'so as to be uncovered by the piston l t at the outer end of its stroke as shown in Fig. 1. Inlet port 18 is arranged to be similarly uncovered by. piston 13, this piston. being long so as to keep the inlet port cov-' ered except at the outer end of the piston stroke. 7

Compression pistons 20 reciprocate in 23 to that part of connecting rod 16 encir-' The inlet ports for the com- 110 cling the crank. pression cylinders are beneath as at 24 and are situated so that they are uncovered at rods 16 there are the outward stroke of the compression piston. These inlet ports are connected with inlet pipes 25 arranged in such a manner that the distance of travel of the gases for all the cylinders is the same, thus insuring that each cylinder will receive its due proportion of the total charge. The outlet ports 26 for the compression cylinders are arranged above and at the end,being connected by pipes 27 to inlet ports 18 of the explosion cylinders opposite.

A' gear 28 meshes wlth gears 29 mounted on the crank shafts and confines the shafts to synchronous rotation in the same direction. "When the engine is started,a charge is drawn into the compression cylinders and is compressed through pipe 27 to port- 18. At the instantof highest compression port 18 is open by the passage ofpiston 13 and the compressed charge flows into the explosion space between pistons 13 and 1 1, forcing any other gases out through exhaust port 17 As the crank shaft continues to rotate the two explosion pistons approach each other and re-compress the charge. At the appropriate instant the charge is exploded through the medium of spark plug 30, and the two pistons thus forced apart. At the same time a fresh charge for the next cycle of operation is being compressed in the compression cylinder, and when the explosion pistons have reached their outermost positions the new charge is admitted, forcing out the burnt gases. On account of the placement of the inlet and exhaust ports at op osite ends of the combustion chamber, no do ector is needed to clean out the cylinders.

Shaft 31 carrying gear 28 may be used as the main drive shaft through which power is transmitted and the relative sizes of gears 28 and 29 may be able to suit the speed desired for shaft 31. Shaft 31 and the gears may-be duplicated on the other end of the engine so that power may be taken from both ends if desired.

One of the distinctive features of advantage in the present invention is the utilization of a single c linder for two pistons, the weight of this single cylinder being much less than two cylinders designed to carry one piston each. With only a single cylinder into which to feed the charge'it is thus easily rendered that one compression cylinder serves for two explosion pistons; this fact reducing wei ht and com lications. It will be understoo that the c earance space between the two explosion pistons is of about twice the capacity as is used between a single piston and its cylinder head, for

the same compression; and that, therefore,

with the same amount of fuel which would be used in an engine of like number of pistons I obtain the same efiiciency and power with a very material reduction of weight.

Having described my invention, I claim 1. An internal combustion engine, comprising a frame, an explosion cylinder open at both ends mounted on the frame, a pair of pistons in the cylinder and inclosing an explosion space between them, cranks mounted on the frame one adjacent each end of the cylinder, connecting rods between the cranks and the pistons, a compression cylinder mounted on the frame adjacent one of the cranks and on the opposite side there of from the explosion cylinder, a piston in the compression cylinder, a conneetin rod between the compression piston an the crank, means to admit explosive mixture to the compression cylinder, means to conduct a compressed charge of mixture to one end of the explosion space between the two explosion pistons, means to ignite the mixture in the explosion s ace, means to exhaust the burned mixture rom the other end of 'the explosion space, and rotary connecting means between the two cranks.

2. An internal combustion engine, comprising a frame, an explosion cylinder open at both ends mounted on the frame, a pair of istonsin the cylinder and inclosing an exp osion space between them, cranks mounted on the frame one adjacent each end of the cylinder, gears connecting the cranks rotatively together, connecting rods between the cranks and the pistons, a compression cylinder mounted on the frame adjacent one of the cranks and on the opposite side thereof from the explosion cylinder, a piston in the compression cylinder, a bearing pin mounted on the connecting rod connecting the explosion piston with the last named crank, a connecting rod between the pin and the explosion piston, means to introduce combustible mixture to the compression cylinder, means to lead the compressed mixture from the compression cylinder to the explosion cylinder at one end of the explosion space between the two explosion pistons, means to ignite the mixture, and means to exhaust the burnt mixture from the other end of the explosion space.

In witness that I claim the foregoing I have hereunto subscribed my name this 8th day of June 1909.

MARTIN SEARS. Witnesses:

'ELWOOD H. BAnxEnEw,

JAMES T. Banxannw. 

